import math
x1,y1,x2,y2 = map(float,input().split())
x = (x1-x2)**2
y = (y1-y2)**2
print('{:.8f}'.format(math.sqrt(x+y))) import math math x1,y1,x2,y2 = map(float,input().split()) x1 map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 x = (x1-x2)**2 x (x1-x2)**2 x1-x2 x1 x2 2 y = (y1-y2)**2 y (y1-y2)**2 y1-y2 y1 y2 2 print('{:.8f}'.format(math.sqrt(x+y))) print '{:.8f}'.format(math.sqrt(x+y)) '{:.8f}'.format '{:.8f}' format math.sqrt(x+y) math.sqrt math sqrt x+y x y y2 = map(float,input().split()) map(float,input().split()) y2 y1,x2,y2 = map(float,input().split()) map(float,input().split()) y1 x = (x1-x2)**2 (x1-x2)**2 x x1,y1,x2,y2 = map(float,input().split()) map(float,input().split()) x1 x2,y2 = map(float,input().split()) map(float,input().split()) x2 y = (y1-y2)**2 (y1-y2)**2 y
import math
x1,y1,x2,y2 = map(float,input().split())
x = (x1-x2)**2
y = (y1-y2)**2
print('{:.8f}'.format(math.sqrt(x+y)))
